Cephalometric studies of the mandible, its masticatory muscles and vasculature of growing Göttingen Minipigs—A comparative anatomical study to refine experimental mandibular surgery

Abstract

Over many decades, the Göttingen Minipig has been used as a large animal model in experimental surgical research of the mandible. Recently several authors have raised concerns over the use of the Göttingen Minipig in this research area, observing problems with post-operative wound healing and loosening implants. To reduce these complications during and after surgery and to improve animal welfare in mandibular surgery research, the present study elucidated how comparable the mandible of minipigs is to that of humans and whether these complications could be caused by specific anatomical characteristics of the minipigs’ mandible, its masticatory muscles and associated vasculature. Twenty-two mandibular cephalometric parameters were measured on CT scans of Göttingen Minipigs aged between 12 and 21 months. Ultimately, we compared this data with human data reported in the scientific literature. In addition, image segmentation was used to determine the masticatory muscle morphology and the configuration of the mandibular blood vessels. Compared to data of humans, significant differences in the mandibular anatomy of minipigs were found. Of the 22 parameters measured only four were found to be highly comparable, whilst the others were not. The 3D examinations of the minipigs vasculature showed a very prominent deep facial vein directly medial to the mandibular ramus and potentially interfering with the sectional plane of mandibular distraction osteogenesis. Damage to this vessel could result in inaccessible bleeding. The findings of this study suggest that Göttingen Minipigs are not ideal animal models for experimental mandibular surgery research. Nevertheless if these minipigs are used the authors recommend that radiographic techniques, such as computed tomography, be used in the specific planning procedures for the mandibular surgical experiments. In addition, it is advisable to choose suitable age groups and customize implants based on the mandibular dimensions reported in this study.

Calcium Phosphate-Coated Titanium Implants in the Mandible: Limitations of the in vivo Minipig Model

“…Minipigs are an established animal model for testing implants and bone repair material [26][27][28][29]. However, in 2019 a cephalometric study of the minipigs mandible revealed anatomical differences to the human mandible with potential complications in mandibular surgery research [30]. Our surgical procedures of tooth removal and implant insertion were similar to other studies [27,31].…”

Patient‐Specific Bioimplants and Reconstruction Plates for Mandibular Defects: Production Workflow and In Vivo Large Animal Model Study

“…The bone remodeling rate, defined as the volume of bone turned over per unit volume of tissue per day, is 10% per month in pigs, compared with 3% per month in humans. [ 21–23 ] With these aspects in mind, interpretation of our findings in a human clinical setting demands cautiousness.…”

Macroscopic, morphometric, and tomographic features of the mandible of the collared peccary (Pecari tajacu) applied to clinical morpho‐physiology and imaging

“…Afterward, the mandibular morphometry was performed by a single examiner and in duplicate using the Starrett® digital electronic caliper (capacity 0–150 mm; resolution 0.01 mm; and accuracy ± 0.02 mm). As recent information specific to this context is scarce regarding artiodactyl animals in general (Corte et al, 2019; Özkan et al, 2020; Paulo et al, 2020; Sundaram et al, 2019), much of the measurements adopted here were also based on and adapted from studies with specimens from the order Carnivora (Barroso et al, 2009; Igado, 2014; Magalhães, Ferreira Júnior, et al, 2019; Magalhães, Romão, et al, 2019; Maximiano Neto et al, 2020; Souza Junior et al, 2013, 2016).…”